finish/clean up julia2 course slides

2023/2023-03-09_ProgrammingWithJulia-2/slides/2a-details.md

@@ -6,82 +6,11 @@
 <i class="twa twa-mechanical-leg"></i>
 <br>
 Compiler &amp; language internals
+(part 1)
 </div>
 
 
 
-# What is this "compiled code"?
-
-You can inspect various stages of code representation (and reveal bugs):
-
-- `code_lowered(+)`
-- `code_typed(+)`
-- `code_typed(+, (Int, Float64))`
-- `code_llvm`
-- `code_native`
-
-What happens if we use an abstract type?
-
-
-
-<center style="font-size:200%; line-height:120%; margin-bottom: 1em">
-Performance rule #1:<br><br>
-<strong>Less instructions is typically better,</strong><br>
-<strong>less jumps is typically much better.</strong>
-</center>
-
-
-
-<center style="font-size:200%; line-height:120%; margin-bottom: 1em">
-Performance rule #2:<br><br>
-<strong>Memory allocations comprise of many instructions<br> and plenty of jumps.</strong>
-</center>
-
-
-
-# What are all these things starting with `@`?
-
-Macros allow you to generate code before compiler runs it:
-- `@info` can know what variable names to display
-- `@benchmark` can run the code several times
-- `@test` can safely wrap the failing code and print what failed
-
-## Important types for macros:
-
-- symbols: `:abc`, `:+`, ...
-- expressions: `:(1+2)`, `quote ... end`
-
-Macros are functions that get unevaluated arguments (as expressions) and return unevaluated results (as expressions).
-
-```julia
-macro clear_data(v)
-  quote
-    $(Symbol(v, :_orig)) = load_original_data()
-    $(Symbol(v, :_enriched)) = nothing
-    $(Symbol(v, :_final)) = nothing
-  end
-end
-
-@clear_data patients   # reloads patients_orig, clears patients_enriched, patients_final
-```
-
-
-
-# Macro use-cases
-
-Use macros to improve your code whenever Julia syntax is too unwieldy.
-
-```julia
-model = @reaction_network MyModel begin
-    c1, s + i --> 2i
-    c2, i --> r
-end
-```
-
-(Taken from `Catalyst.jl`)
-
-
-
 # How do I package my code?
 
 Use `] generate MyPackageName`.
@@ -106,24 +35,3 @@ using Test, MyPackageName
   @test f() == 123
 end
 ```
-
-
-
-# How do I document my code?
-
-Docstrings are automatically sourced and exposed to the help system (and `?`)
-
-```julia
-"""
-    f()
-
-This returns a pretty good randomly chosen constant.
-"""
-f() = 123
-```
-
-Extra packages:
-- `Documenter.jl` makes a nice website out of the documentation
-  - (and uploads it to e.g. github pages)
-- `DocStringExtensions.jl` provide some macros to simplify writing docstrings
-  - (e.g., typesetting of the full function type signature)